The correct option is: A) Longest: 40 inches, Middle-sized: 20 inches, Shortest: 10 inches
Let's represent the lengths of the three pieces as follows:
Longest piece: L
Middle-sized piece: M
Shortest piece: S
The problem states that the longest piece is twice the length of the middle-sized piece, which can be expressed as:
L = 2M
The shortest piece is 10 inches shorter than the middle-sized piece, which can be expressed as:
S = M - 10
We also know that the total length of the three pieces is 70 inches, which can be expressed as:
L + M + S = 70
(2M) + M + S = 70
Combine like terms:
3M + S = 70
Substitute the second equation (S = M - 10) into the above equation to get:
3M + (M - 10) = 70
4M - 10 = 70
Add 10 to both sides:
4M = 80
M = 20
L = 2(20) = 40
S = 20 - 10 = 10
Longest: 40 inches, Middle-sized: 20 inches, Shortest: 10 inches